connecting 2 bezier curve segments
I would suggest that after creating your two paths, you convert each one to a mesh, then you Join Ctrl+J the two new meshes, then in Edit Mode you select segments of vertices on each side and make a new Face.

The reason you should select a small segment at the time is if you were to take the whole thing there is a risk that it creates one large face that can cover the hole in the middle. You can use the Circle select to grab a set of vertices.

Hope this works for you.